1. Field of the Invention
The technical field of the present invention relates to a display device and a driving method thereof.
2. Description of the Related Art
As a display device which is thin and lightweight (a so-called flat-panel display), a liquid crystal display device including a liquid crystal element, a light-emitting device including a self-light-emitting element, a field emission display (an FED), and the like have been competitively developed.
In addition, since many optical members such as a polarizing plate and a backlight are used in a liquid crystal display device, there are problems with the liquid crystal display device in that, for example, cost or power consumption needs to be reduced.
As a measure against the above problems, a liquid crystal display device in which a polarizing plate and/or a backlight are/is necessarily involved and image display is performed by utilizing scattered light with a liquid crystal such as a Polymer Dispersed Liquid Crystal (PDLC) or a Polymer Network Liquid Crystal (PNLC) has been researched (see Non-Patent Document 1, for example). With the display device, high visibility equivalent to paper on which pictures or characters are drawn can be obtained.
Further, attention has been given to a display device provided with a light-detecting sensor (also referred to as a photosensor) (see Patent Document 1, for example). This display device can recognize the touch of an object on a display panel or the approach of an object to a display panel by detecting light. That is, the display device is equipped with a so-called touch recognition function.